Apparatus for annealing glassware



April 29, 1930. G. E. HOWARD APPARATUS FOR ANNEALING GLASSWARE Filed Jan. 20 1926 A) @w V xKQy xy QM Patented Apr. 29, 1930 UNITED STATES PATENT! OFFICE GEORGE E. HOWARD, OF BUTLER, PENNSYLVANIA, ASSIGNOR TO HARTFORD-EMPIRE COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF DELAWARE APPARATUS FOR ANNEALING GLASSWARE Application filed January 20, 1926. Serial 1T0. 82,421.

This invention relates to apparatus for annealing glassware and it has particular relation to lehrs of the tunnel type through which a series of articles of glassware are trans orted by an endless conveyor and subject while in the tunnel, to varying temperature environments in order to relieve stresses and strains that may exist therein.

One of the objects of the present invention is to rovide a lehr, of the type described,

that is re atively simple in operation and construction and which is particularly adapted to utilize the air supply of the factory where it is installed, for controlling the temperature in the tunnel.

Other objects of the invention will appear from the following description and the appended claims.

In the accompanying drawings,

Figure 1 is a vertical longitudinal sectional view of the forward portion of a lehr constructed in accordance with the invention;

Figure 2 is a similar view of the rear portion of the lehr shown in Fig. 1;

Fig. 3 is a vertical transverse sectional view through the lehr taken on line 3-3 of Fig. 1;

Fig. 4 is a similar'view taken on line44= of Fig. 1; and

Fig. 5 is a fragmentary vertical longitudiao nal sectional view illustrating a modified form of roof construction. 1

Referring to the drawings, a lehr constructed in accordance with the invention is shown as comprising a tunnel 1 having a bottom 2, side walls 3 and a top or roof 4 and supported at intervals upon pedestals 5.

Ware is transported through the tunnel by an endless conveyor .6, the ware-bearin strand of which is supported by the floor 0 the tunnel and by a sorting table 7. The conveyor is driven by any suitable mechanism, herein'shown as comprising a drum 8, reduction gearing 9 and idler rollers 10. The idle strand of the conveyor returns to the entrance end of the lehr beneath the tunnel and is supported at intervals by rollers 11. At the forward end of the lehr the conveyor asses upwardly and around rollers 12 and t ence mto the tunnel.

The tunnel is heated by a plurality of burn- 1 nel.

ers 13 carried by a series of gas pipes 14 which are supplied with fuel by a common pipe 15 preferably communicating with the factory gas supply. The pipes 14 are mounted beneath a hood or apron 16 which constitutes the floor of the forward end of the tunnel and over which the conveyor passes upon entering the tunnel. These pipes 14 are inclined downwardly from the forward end of the lehr so'as to gradually reduce the amount of heat applied to the tunnel, it bein known that the heating effect of a flame ecreases the further it is removed from the object towards which it is directed.

For substantially one-half of the length of the tunnel the bottom, sides and top thereof are covered with a heat-insulating material 17 which decreases in thickness rearwardly, and. for the remainder of the length of the tunnel the insulation is dispensed with, ex osing the bare metallic walls to the cooling e ect of the outer atmosphere. The top of the rear or exit portion of the tunnel 1s also dispensed with so as to hasten the dissipation of heat from the ware, the side walls preventing undue cooling b air currents. The object of this constructlon is to retard the dissipation of heat from the ware during a portion of its travel through thetunnel so as to relieve the strains existing therein and to thereafter accellgrate the rate of cooling as rapidly as poss1 e.

In order that the temperature curve in the tunnel may be controlled at will, cooling air is projected at intervals against the top and the bottom of the tunnel through a plurality of damper-controlled nozzles 18 and 19 which respectively communicate with wind pipes 20 and 21 which extend longitudinally above and below the tunnel. The pipe 20 communicates directly with an air supply pipe 22 and the pipe 21 communicates with the supply pipe 22 through branch pipes 23 disposed one on each side of the tun- The nozzles 18 and 19 are disposed at an angle to the vertical so that the air pro-' ceive air from the ordinary air-lines of the glass factory.

By regulating the dampers in the nozzles 18 and 19, the amount of cooling air projected against the tunnel may be controlled at will, thereby rendering it possible to obtain the proper drop in temperature in the tunnel according to the req uirementsof the particular type of ware being annealed.

After the dampers in the nozzles 18 and 19 have been set so as to project volumes of air against the top or bottom of the tunnel, or both, in the proper proportions longitudinally thereof to produce the necessary temperatures in the tunnel for the proper annealing, the total volume of air thus projected may be increased or decreased in orderto accelerate or retard the rate of cooling according to the particular type of ware being annealed, without disturbing the individual set tings of the dampers, by means of dampers 24 and 25 disposed in the pipes 20 and 21 adj acent to the forward ends thereof.

The insulation 17, at any specified point, has a fixed resistance, proportional to its thickness to the dissipation of heat from the interior of the tunnel. However, it is desirable that the dissipation of heat from the tunnel be variable, in order to properly anneal various types of glassware. I accomplish such variation, notwithstanding the fixed thermal resistance of the insulation, by means of the air nozzles 18 and 19 which are directed against the insulation 17 for the purpose of increasing or decreasing to any desired extent, the amount of such dissipation of heat to conform to the varyin requirements of the ware within the tunne The amount of insulation must be sufficient at any cross-section of the tunnel to reduce the dissipation of heat to the minimum necessary in the extreme case, such as the annealing of small Ware. A more rapid dissipation of heat necessary in annealing heavier or hotter Ware may be obtained by the application of air from the nozzles 18 and 19.

Inasmuch as there is in all cases a dropping of temperature of the ware as it is transported through the tunnel, and inasmuch as the rate of cooling can usually be increased as the ware passes through the tunnel, it follows that both these conditions will allow a reduction in the thickness of the insulating material toward the exit end of the tunnel.

In Fig. 5 a modified roof construction is illustrated. In this construction the roof is provided with a plurality of corrugations 24, and nozzles 26 project jets of air vertically against the roof. By so doing, the heat-dissipating surface area of the roof is increased, and the air projected against the roof also exerts a scouring action, as is indicated by the arrows.

From the foregoing it will be apparent that there is provided a lehr of very simple construction, and one that may be operated very conveniently from the ordinary gas and air supply systems of the factory wherein it is installed.

The illustrated embodiment of the invention may be modified in construction and arrangement without departin from the scope of the invention as set forth 1n the appended claims. For example, the burners may be continued for a greater distance beneath the floor of the tunnel so as to increase the length of the heated zone in the tunnel and also it may be found desirable to dispose burners and air nozzles alternately beneath the floor so as to insure against a too sudden drop in the temperature of the tunnel where the heated zone therein merges into the cooling zones.

I claim as my invention:

1. An apparatus for annealing glassware, comprising a tunnel having a wall exposed to the influence of the outer atmosphere, and means for directing an unconfined cooling medium against said wall at intervals longitudinally thereof to control the temperature gradient in said tunnel.

2. An apparatus for annealing glassware, comprising a tunnel having a wall varying in thermal conductivity longitudinally thereof, and means for directing a cooling medium against said wall in varying quantities at intervals longitudinally thereof to control the temperature gradient in said tunnel.

3. An apparatus for annealing glassware comprising a tunnel having a wall varying through successive sections in thermal conductivity, and means for directing a plurality of streams of cooling air against said wall at intervals longitudinally thereof to control the temperature in said tunnel.

4. An apparatus for annealing glassware, which comprises a tunnel having a wall of relatively high thermal conductivity exposed to the influence of the outer atmosphere, means for heating said tunnel, and means for directing jets of cooling air against the outer surface of said Wall at intervals longitudinally thereof to control the temperature in said tunnel.

5. An apparatus for annealing glassware, which comprises a tunnel having a wall exposed to the influence of the outer atmosphere, means for directing heating and cooling media against the outer surface of said wall at selected intervals longitudinally thereof to control the temperature in said tunnel.

6. An apparatus for annealing glassware, which comprises a tunnel having walls of relatively high thermal conductivity, means for projecting an unconfined heating medium against one of said walls, means for projecting an unconfined cooling medium against another of said walls at intervals longitudinally thereof, and means for controlling the amount of heating and cooling media projected against said walls to control the temperature in said tunnel.

7. An apparatus for annealing glassware,

comprising a tunnel having a metallic wall ,exposed to the influence of the outer atmosphere, means for projecting unconfined streams of cooling air against said wall in regulable quantities at intervals longitudinally thereof to control the temperature in said tunnel.

8. Anapparatus for annealing glassware, comprising a tunnel having a metallic wall exposed to the influence of the outer atmosphere, means for projecting unconfined streams of a heating medium against said wall in regulable quantities at intervals longitudinally thereof to control the temperature in said tunnel.

9. An apparatus for annealing glassware, comprising a tunnel having a metallic top wall and a metallic bottom wall both of said walls being exposed to the influence of the outer atmosphere, means for rojecting unconfined streams of cooling am against said top wall at intervals longitudinally thereof, and means for independently projecting unconfined streams of cooling air and a heating medium against said bottom wall at predetermined points longitudinally thereof to control the temperature in said tunnel.

' uninsulated walls a or the remainder of its 10. An apparatus for annealin glassware comprising a tunnel having wal s provided with a heat insulating material of gradually reducing thickness and means for rojecting a cooling medium against said'wa in regulable quantities and at selectedintervals longitudinally thereof.

11. An apparatus for annealing glassware comprising a tunnel provided with heat insulated walls for a ortion of its length and length, and means for projecting an unconfined stream of a cooling medium against the outer surfaces of said walls in regulable quantities and at selected intervals longitudinally thereof.

12. An apparatus for annealing glassware comprising a tunnel having a metallic floor and a plurality of burners for heating'said floor and disposed at increasing distances therefrom longitudinaly thereof.

13. Apparatus for annealin glassware comprising a tunnel having a wa l exposed to the influence of the outer atmosphere, and means for directing a plurality of longitudinally and laterally spaced streams of temperature controlling media against the outer surface of said wall to control the temperature gradient in the tunnel.

Signed at Hartford, Connecticut, this 12th day of January, 1926.

GEORGE E. HOWARD. 

